1. Field of the Invention
The present invention relates to a technology for eliminating noise from a microphone, particularly to a microphone array structure able to reduce noise and improve speech quality and a method thereof.
2. Description of the Related Art
Microphones may pick up audio signals by a single-channel or dual-channel way. In a single-channel microphone system, the signal/noise ratio (SNR) thereof should be taken into consideration. In a dual-channel microphone system, microphones are arrayed to form a directional microphone system according to a beamforming technology. The directional microphone system is less sensitive to background noise but more sensitive to human voices. The directional microphone system is pointed to a person to receive his voices. However, the beam formed by two microphones is very large, and the directionality thereof is insufficient.
The common devices to reduce indoor or in-vehicle noises for mobile phones usually adopt numerous microphones, various filters and a great amount of matrix computation, which greatly increase the hardware cost of a mobile phone. Further, directionality of the conventional technologies, which have existed in products, patents and documents, is too low to effectively reduce noises without speech distortion.
Accordingly, the present invention proposes a microphone array structure able to reduce noise and improve speech quality and a method thereof to overcome the abovementioned problems. The technical contents and embodiments of the present invention are described in detail below.